I bought two of these drill bits and a Rockler tool and was very excited. The jig seems to be good. I just tested this on some cut birch plywood and had to print out this review. The first time the drill fell out of the spring loaded thing, I don't know, the drill wasn't tight enough in it, so I, a newbie, took a hex wrench to tighten the hex nut that holds the screw in the drill. and the whole drill fell apart into a mess - let me tell you it's impossible to put back together. Frustrated withβ¦